1. Field of the Invention
Illustrative embodiments of the present invention generally relate to a powder conveyance unit and an image forming apparatus including the powder conveyance unit, and more particularly, to a powder conveyance unit for conveying powder such as toner, and an image forming apparatus such as a printer, copier, and facsimile machine for forming images with the powder.
2. Discussion of the Related Art
Related-art image forming apparatuses generally include a developing unit, in which developer, containing mainly toner but also carrier particles, is accommodated to develop a latent image formed on an image carrier into a visible image.
Since toner contained in the developer is constantly consumed when developing images whereas the carrier is not, new or unused toner may need to be additionally supplied to the developing unit. Such new or unused toner is conveyed from a toner container provided in the apparatus to the developing unit so as to replenish the developer in the developing unit.
Such related-art image forming apparatus further includes a cleaning unit that collects residual toner remaining on the image carrier after transfer of the toner image from the image carrier to a transfer member. The residual toner collected by the cleaning unit is conveyed to and collected in a waste toner collecting unit or the developing unit for reuse and recycling.
An image forming apparatus that employs a known technique conveys free-falling toner from a toner container to a developing unit via a toner conveyance path in a toner conveyance unit therein. In such a toner conveyance unit, toner particles can adhere to small or narrow gaps or uneven portions on inner walls of a toner conveyance path forming member that forms the toner conveyance path and thus remain in the toner conveyance path after conveyance of toner. The toner particles adhering to the inner wall as described above accumulate with time and become firmly fixed to the inner walls due to changes in ambient temperature and/or humidity in the image forming apparatus. Accumulation of toner particles on the inner walls of the toner conveyance path makes the toner conveyance path narrower, which can cause toner to clog in the toner conveyance path and result in poor toner conveyance.
To counteract this problem, the image forming apparatus employing the above-described known technique may include a toner discharge opening and a rotatably moving or rocking member. The toner discharge opening is disposed on a side wall forming the toner conveyance path to discharge toner to the toner conveyance path. The rocking member, such as a wire, is rotatably movable along a certain area of the inner wall of the toner conveyance path facing the toner discharge opening. By contacting the rocking member against toner particles that adhere to the inner wall facing the toner discharge opening, the toner particles can be removed from the inner wall. Thus, accumulation of toner particles on the inner wall of the toner conveyance path over time can be prevented, which can further prevent that narrowing of the toner conveyance path due to toner particle accumulations.
However, in the related-art image forming apparatus employing the above-described known technique, the rocking member cannot remove toner adhering to areas other than the above-described area of the inner wall of the toner conveyance path. Therefore, toner can accumulate with time onto the other areas of the inner wall of the toner conveyance path, which can cause the toner conveyance path to become narrower, and can result in poor toner conveyance.